As the investigation and her conviction in court evidenced, she was a victim of an abusive, violent and controlling relationship with Huntley who had an evidenced history of being a domestic abuser.
She was a victim of violence from him which was reported not just by her but by neighbours who witnessed it.
Pre-sentencing reports outlined the coercive controlling nature of their relationship where he had isolated and manipulated her.
She also loved him and believed he loved her and he came to her asking her to provide a false alibi as he told her, there were things in his past so that the Police would try and pin it on him but he absolutely didn't do anything to Holly or Jessica. He was desperate for her to believe him, support him and help him. And she didn't at that time, believe he was involved or capable of such heinous crimes. How many people in relationships, even abusive ones think that of their partner?
She didn't actually know or believe at that time that he did it but didn't want to lie to the Police either. But in her defence in court, she said she was frightened of him and felt backed into a corner.
Huntley is confidently giving interviews to TV crews around this time! In her mind, he's not guilty and the Police will figure that out but then what would the consequences be for he from him if she hadn't supported him and lied for him?
It was absolutely right she was convicted and served prison time despite being in an abusive relationship. Mitigating factors don't absolve anyone from responsibility for their crimes.
But that's where it should end. She shouldn't be hounded, harassed or have people on SM say she probably knew and didn't care or that she should have been executed.